POLICE were totally unaware speeding repeat drink-driver Brett Glenbar had run down and killed a Brisbane couple when they initially caught up with him three years ago.

The Brisbane Supreme Court was told officers only stumbled across the tragedy when they found half of the remains of one victim - which had crashed through the windshield - in the rear of Glenbar's rented car more than 3km past the initial crash site.

The court was told Glenbar, who has two previous drink driving offences, was driving with a blood alcohol level up to four-and-a-half times the legal limit and at speeds in excess of 135km/h when he struck and killed Ronald Ellison, 46, and Jacqueline Sylvester, 40.

Glenbar, 45, was jailed for 10-years after pleading guilty to two counts of manslaughter and one of causing grievous bodily harm on Chambers Flat Rd, Park Ridge, on Brisbane's southside, about 9.55pm on December 4, 2009.

He also pleaded guilty to charges of drink-driving, speeding, leaving the scene of an accident, and failing to stop for police.

Prosecutor Ben Power said Phillip Choi Chang, who was a passenger in Glenbar's car, received severe facial injuries when Ms Sylvester's severed upper body slammed through the windscreen, into him and came to rest in the rear passenger seat.

Mr Power said Glenbar had been driving at high speeds when he realised a passing police car, which recorded his speed at 135km/h, did a u-turn to follow him.

The court was told police did not take part in a pursuit, but officers noticed Glenbar's car increase speed greatly in a bid to evade them.

Mr Power said Glenbar did not stop after mowing down and killing Mr Ellison and Ms Sylvester, forcing one car off the road as he clipped it while trying to overtake it, and then slamming into a road sign.

He said when police eventually caught up with Glenbar he told them he thought he might have just done something bad.

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